Benzo(a)pyrene in Brazilian vegetable oils

Samples of vegetable oils on the Brazilian market including rape seed, corn, soybean, sunflower, rice, palm and garlic were analysed for benzo(a)pyrene (B(a)P). The analytical method involved liquid-liquid extraction, clean-up on silica gel column and determination by high performance liquid chromatography using fluorescence detection. The limit of detection was 0.5 mu g/kg. Benzo(a)pyrene was detected in almost all samples, at levels up to 58.9 mu g/kg. The mean levels of B(a)P in rice, sunflower, soybean, corn and palm oils were 1.8, 0.2, 2.2, 10.8 and 2.1 mu g/kg respectively. No B(a)P was detected in garlic and rape seed oils. The data indicate that the levels of B(a)P found in Brazilian corn oils are relatively higher than those published in the literature for European corn oils.13663964

Benzo(a)pyrene in olive oils on the Brazilian market

Benzo(a)pyrene (B(a)P), the best known of the carcinogenic PAHs, has been found at variable concentrations in several foods. In this study 40 samples of various olive oils available in Brazil were analysed for B(a)P. The analytical method involved extraction by liquid-liquid partition, clean-up on silica gel and analysis by high performance liquid chromatography with a fluorescence detector. Benzo(a)pyrene was found in almost all samples, at levels up to 164 mu g/kg. The lowest levels of B(a)P were detected in olive oils imported from the major European countries. Olive oils imported from Europe but packed in Brazil and olive oil blended with soybean and corn oils showed relatively higher levels of B(a)P, ranging from 0.9 to 9.7 mu g/kg and from 2.2 to 9.2 mu g/kg, respectively.55218518

HPLC analysis of carotenoids in orange juice

Lutein, zeaxanthin, beta-cryptoxanthin, alpha-carotene and B-carotene have been determined in samples of Brazilian orange juice (Citrus sinensis). The concentrations found in factory-produced concentrates have been compared with those obtained on the Brazilian retail market and with authentic hand-squeezed juices. The analyses of the latter enabled a comparison of varieties to be made. A concentration range of 0.11-1.21 mg litre(-1) was determined for total carotenoids with beta-carotene, the most important source of Vitamin A, being found in the highest concentration in the Pera variety followed by Val (e) over cap ncia, Natal, Lima and Baia varieties. The total carotenoids present in samples of frozen concentrated orange juice (FCOJ) obtained from factories ranged from 0.26-0.48 mg litre(-1), while retail samples of this product contained slightly more (0.46-0.81 mg litre(-1)). Frozen concentrated orange pulp-wash presented much lower concentrations, ranging from 0.04 to 0.08 mg litre(-1) of total carotenoids. Fourteen samples of retail freshly-squeezed orange juice contained carotenoids ranging from 0.04 to 0.55 mg litre(-1), with only one sample out of the range found for authentic samples. This could be due to the addition of pulp-wash to this sample, in which undeclared sorbic acid was also detected. (C) 1998 Elsevier Science Ltd. All rights reserved.64226927

Flavanone glycosides in Brazilian orange juice

Authentic samples of oranges, frozen concentrated orange juice and pulp-wash, and retail samples of freshly squeezed orange juice and frozen concentrated orange juice have been collected in Brazil and analysed for the flavanone glycosides (FG) narirutin and hesperidin by reversed phase HPLC with UV detection at 280nm. The juice from hand-squeezed fruit gave narirutin and hesperidin concentrations of 16-142 mgl(-1) and 104-537 mgl(-1), respectively. The ratio of hesperidin to narirutin showed varietal difference with Pera having the highest ratio (mean 8.4) and Baia the lowest (3.6). Frozen concentrated orange juice contained higher quantities of FG with narirutin ranging from 62 to 84 mgl(-1) and hesperidin from 531 to 690 mgl(-1) (after dilution to 12 degrees Brix). In frozen concentrated orange juice pulp-wash, the narirutin level ranged from 155 to 239 mgl(-1) and hesperidin from 1089 to 1200 mgl(-1). The analysis of 23 samples of freshly squeezed juice from the Brazilian market place showed that the FG content of most samples (9.1 to 94.8 and 105.8 to 586.6 mgl(-1), respectively, for narirutin and hesperidin) was similar to those found for authentic ones, indicating that these orange juices were not adulterated. (C) 1998 Elsevier Science Ltd. All rights reserved.61327528

CONVERSION OF SUCROSE TO ISOMALTULOSE BY MICROBIAL GLUCOSYLTRANSFERASE

Screening of glucosyltransferase-producing microorganism was performed and one strain of Klebsiella sp., produced intracellular enzyme. The enzyme was purified and characterized. Maximum conversion of sucrose to palatinose was 86% at 25 C.14754755

Polymethoxylated flavones in Brazilian orange juice

Sinensetin has been quantified in authentic samples of Brazilian orange juice. In addition, six further polymethoxylated flavones (PMFs) have been determined in terms of their relative amounts. The PMFs were extracted into toluene and analysed using reversed phase HPLC with detection at 340 nm. Peak identification was based on the UV-visible spectra and the elution order described in the literature. Hand-squeezed orange juices contained a mean of 0.10 (SD 0.04) mg(-1) sinensetin with the highest concentrations found in Pera and Natal varieties. Commercial samples of frozen concentrated orange juice (FCOJ), frozen concentrated pulp-wash (FCOPW), retail FCOJ and retail freshly squeezed orange juice (FSOJ) typically contained at least ten times more sinensetin than those found for samples squeezed by hand. The PMFs peak area ratios for these sample classes were examined further using canonical discriminant analysis. This procedure could distinguish the hand-squeezed juices of Pera and Hamlin varieties from those of Natal and Valencia. Similarly, hand-squeezed juices could be readily distinguished from the commercial samples of FCOJ, FCOPW, retail FCOJ and retail FSOJ. (C) 1998 Elsevier Science Ltd. All rights reserved.63451351

Total lipids and fatty acids of strains of Metarhizium anisopliae

Two growth stages, conidia (C) and mycelium (M), and two media, minimal medium (MM) and complete medium (MC), were compared in 10 strains of M. anisopliae, and two strains of M. anisopliae var, majus were similar in percentages of total lipids. Tukey test for average of lipid content. in conidia (C) and mycelia (M) cultured on minimal (MM) and complete (MC) media showed significant differences between means at the 5% level for mycelia and conidia, indicating variability in total lipid production and storage during growth. Strains 5 and 7, both variety majus, did not present sizable differences from variety anisopliae. For fatty acids, C18:1 and C18:2, oleic and linoleic, respectively, the differences were all highly significant (p=1%) with the highest means being obtained for conidia for fatty acid C18:1 and for myclelia for fatty acid C18:2.31212112

Use of isotopic analyses to determine the authenticity of Brazilian orange juice (Citrus sinensis)

Isotopic analysis was used to characterize authentic samples of orange juice (Citrus sinensis) from Brazil. Site specific natural isotopic fractionation nuclear magnetic resonance (SNIF-NMR) was used to determine deuterium/hydrogen ratios at the methyl [(D/H)(I)] and methylene [(D/H)(II)] sites of ethanol produced by fermentation of orange juice. Stable isotope ratio mass spectrometry (SIRMS) was used to determine the ratio of carbon isotopes (C-13/C-12) in the same ethanol and the ratio of oxygen isotopes (O-18/O-16) in the citrus juice water. The mean ratios found for these parameters in authentic hand-squeezed orange juice were as follows: (D/H)(I), 102.3 ppm (SD = 1.7); (D/H)(II), 126.5 ppm (SD = 1.8); C-13/C-12, delta(13)C = -26.6 parts per thousand PDB (SD = 0.9); and O-18/O-16, delta(18)O = +2.27 parts per thousand SMOW (SD = 2.48). Retail samples taken from the Brazilian market place were evaluated by comparison against these data. No evidence was found for the addition of sugar to orange juice or for the dilution with tap water of samples labeled as freshly squeezed.4641369137